<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="../js/jquery-3.4.1.min.js"></script>
		<script>
			$(function(){
				$("#b1").click(function(){
					//$("#pic").addClass("c");
					$("#pic").toggleClass("c");
				});
			});
		</script>
		<style>
		  .c{
			  border:10px groove yellow;
			  border-radius: 50%;
		  }
		</style>
	</head>
	<body>
		<div><img src="../day7/img/3.jpg" id="pic"></div>
		<p>
			<button type="button" id="b1">改变图片的css</button>
		</p>
	</body>
</html>
